Hello there I have a mud drag pickup with a 454 bored .030, 781 heads 10.25 compression with a 268 cam, It makes pretty good power, but it seems lately that I have a miss at idle and I can tell its not as smooth as before when I free rev it. New AED Carb 750hp. Motor was new at begining of year with about 8 races on it. Plugs, Taylor wires, and optima battery new when put motor in, The question is I using my brothers mallory HEi disributor, its about 5 years old I'm thinking thats the problem but I don't know what I should get to replace it. I would appreciate any suggestions from you guys what would be best for it. I don't get over 6000 RPM. I was thinking going with the MSD 6AL but I don't really think I need to spend that much money for onlly running 5800 RPM. Also running pure racing gas. Thanks